When I began the perils of teaching, I, like many other new teachers, chose the generic consequences such as loosing a recess and after school detention. Soon to find out that both are a little much for minor situations like talking out of turn. For these behaviors, I made the mistake of giving multiple warnings. So, to avoid seeming unfair and the self inflicted punishment of monitoring students during extended hours, I became a push-over.
New teachers and new parents need not fall into such a trap that undermines their whole management system. The solution is simply to give a smaller and timely consequence like the popular "time out." And, the key is to give only one warning before issuing the consequence. Doing so shuts the unwanted behavior down quickly, and really helps the teacher to keep control.
We all know that dealing with the little things helps to prevent the big things from arising. Also, let the student to join the group when he/she shows readiness. No research says that arbitrary time intervals are necessary for behavior modification.